SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb0d268088203aac38dfa85651e4b757d9919ce19bf4d1aa134161ec40ac7d0b' 
  AND token = 'CZY3JyiefbyDPs5zHfK9owLwEFyBg+U/w7OcZWQWTvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}